Mainspring-fastener for watches



(No Model.)

P. H. GORTHELL. MAINSPRING FASTENBR FOR WATCHES.

Patented Dec. 28,1897.

MW 5M1 2612M,

UNITED STATES PATENT @rnren,

FRED II. GORTHELL, OF ELGIN, ILLINOIS, ASSIGNOR TO THE ELGIN NATIONAL IVATCII COMPANY, OF CHICAGO, ILLINOIS.

MAlNSPRlNG-FASTEINER FOR WATCHES.

SPECIFICATION forming part of Letters Patent No. 596,395, dated December 28, 1897.

Application filed January 14:, 1897. Serial No. 619,263. (No model.)

To all whom it may concern.-

Be it known that I, FRED H. COR'I'HELL, of Elgin, in the county of Kane, and in the State of Illinois, have invented certain new and useful Improvements in Safety-Barrels for WVatches; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, in which Figure 1 is a perspective View of a portion of a safety-barrel and a brace which operates to connect the outer end of a mainspring therewith. Fig. 2 is an elevation from the outer side of the brace and connected portion of the mainspring; and Fig. 3 is a section of the barrel upon a line parallel with its rim, showing the formation of the portion thereof for engaging the mainspring-brace.

Letters of like name and kind refer to like parts in each of the figures.

The object of my invention is to afford increased strength and security for the connection between the outer end of a mainspring and the barrel; and to such end said invention consists, broadly, in attaching a mainspring to or with the head of a springbarrel, substantially as and for the purpose hereinafter specified.

In the carrying of my invention into practice I provide within the head of a springbarrel A an opening a, which is located concentrically at or very near the inner face of the periphery, has a width equal to about twice the thickness of the mainspring B, and, preferably, a length equal to about six times its width. At the front end of the slot is provided a pawl a,that bodily projects rearward and downward and at its outer end has an upwardly and forwardly inclined face a.

The mainspring B has attached to its outer face at its rear end a brace O, which is formed of sheet metal, and upon its upper edge is provided with a lip c, that extends upward and has such dimensions as to enable it to pass into and vertically fill the opening a in the barrel-head A. The front end 0 of said lip has an inclination which is exactly opposite to the inclination of the front end a of the pawl a, so that when said spring is in place within said barrel, with its lip contained within said opening a, said inclined surfaces will coincide and a strain in a forward direction upon said spring will cause said brace and spring end to be firmly held in position longitudinally and to be also pressed upward against said barrel-head. In order to give increased strength to the connection between said pawl and spring, the en gaging face 0' of the brace 0 extends below the upper edge of the spring, and the latter being cut away upon the same lines enables said pawl at its point to engage with both brace and spring. In order that the lip c of the brace C may freely enter the opening a and yet be firmly held in position laterally while it is engaged with the pawl a, such opening has its width increased rearwardly from a point near its front end.

This construction affords a cheap and sub stantial connection between the spring and barrel, without in any manner weakening the peripheral portion of the latter, and while preserving the desirable feature of the brace obviates the use of a separate hook.

Having thus described my invention, what I claim is 1. As a means for connecting a mainspring to a barrel, a pawl projecting inwardly from the barrel-head, having its end inclined, and a projection on the spring, engaging said end, and having a correspondiugly-inclined surface, substantially as and for the purpose set forth.

2. As a means for connecting a mainspring to a barrel, a pawl projecting inwardly from the barrel-head, and engaging a projection on a brace attached to the spring, anda notch in the spring, substantially as and for the purpose specified.

3. As a means for connecting a mainspring to a barrel, a pawl projecting inwardly from the barrel-head, and engaging a notch in the spring and a projection on the brace extending above the edge of the spring into an open ing in the head, adjacent to the pawl, substantially as and for the purpose specified.

4:. As a means for connecting a mainspring to a barrel, a pawl formed of a portion of the barrel-head, and inclining inward therefrom, and a projection on the spring, engaging the pawl, substantially and for the purpose set forth.

10 tends downward and rearward and is adapted to engage the oppositely-inclined end of said lip, substantially as and for the purpose shown and described.

111 testimony that I claim the foregoing I have hereunto set my hand this (3th day of I 5 January, 1897.

FRED II. CORTI'IELL. Witnesses:

CARLOS H. SMITH, DIIORTIMER M. CLOUDMAN. 

